Bringing only Hazou and Kagome makes things a lot trickier for us. As has been mentioned previously, Hazou and Kagome don't have much firepower between them, even with sealtech, and if we ever need to fight down enemy ninja to achieve our objective this will be a very large penalty to our odds of success. These scenarios include:
- If there are Jounin-tier guards at the rift site
- If the Akatsuki catch up to us (while we're on prepared ground and therefore have a prayer of victory)
- If hunter-nin from anywhere else happen across us while we resupply or acquire intel about the state of the world
- If any of the mystical sites we visit have dangerous entities like the vine golems in Honey
- Anyone we wind up fighting for the sake of combat unstagnations.
Not all of these are guaranteed to happen, but between all of them it feels very likely to me that we will need to lean on Jounin-tier combat power at minimum to achieve our objectives. Not having that means we need backup strats, slower and less efficient when we're trying to race Sasori as fast as we can.
The reason why it's a tempting option, to me, is that it means we might be able to fake our death. Hazou alone sets up a realistic scenario where it looks like he failed a seal and died, happens to the best of us. Kagome is left distraught by this (or so Mari will say, to cover for him), secluding himself in his room all hours of the day, until a few weeks later he just... vanishes into the night. Hazou dead and Kagome missing of his own accord is, I think, a story Leaf and the Akatsuki might buy. Kagome presumably decided he'll go rescue Hazou from the afterlife all on his own, but the Akatsuki don't consider him a threat and never threatened him in the first place, so Leaf remains safer. In the court of public opinion within Leaf, Hazou's death is a tragedy and Kagome's betrayal is perhaps survivable: he was always the most crazy Goketsu, and many would say that they always expected it would go this way eventually. With Mari steering the ship, the Goketsu could likely survive, and Leaf would survive, and the harm of us going missing would be minimized.
...but the problems from above still remain. Getting anyone else to join us becomes increasingly difficult (how exactly is Noburi supposed to fake his death in these conditions without raising suspicion, let alone Mari?). In terms of actually getting necromancy done, in terms of winning the race, this route does far more harm than good. The question becomes "are we so confident in our success that we can afford to eat into our margins of success?" and I, personally, am not. If we want to do this at all, if we're putting everything on the line to see necromancy happen, we can't afford to bring any less than our very best.
